Maid of honour acceptance

[MrsOsM]

My sister booked her wedding venue a couple of weeks ago for a couple of years time. I knew she wanted me to be maid of honour and she knows I'm honoured to do it.
This morning I got a card through the door while DH was at his sisters house, it was in a red envelope and only had my name on it. I thought it was a Valentine's card from DH, we don't usually do Valentine's day but he had given me sweets and chocolates this morning. When I opened it, it was a folded sort of concertina style card that read

I might pee on you

I should say I am currently pregnant and suffering morning sickness worse than in my previous pregnancies and this made me feel a little more sick. When I opened it, it turned out to be from my sister and the card asked me to hold her dress while she pees and run errands for her and asks me to be maid of honour.
The card is very typically my sister's sense of humour. I'm very amused and can actually imagine her laughing as she was buying/writing it.
I would like to respond with an equally as cheeky/funny card but can't find many and I'm not keen on the ones I do find. I have seen ones that are ok but say bridesmaid and not maid of honour so they are not any good.
My sister was my bridesmaid but i got married abroad and there was a total of 6 people there including my young DD so didn't do any of this sort of thing.
Can anyone point me in the direction of where I can get a funny maid of honour acceptance card? Has anyone had anything similar when planning their weddings?
Any help is appreciated.

[catmumof1]

It's the opposite way around but I got my bridesmaids Boomf pop up cards, potentially as horrifying hilarious as a pee themed card?

[LoniceraJaponica]

When you reply may I suggest you put as a proviso that you don't have to organise an expensive hen do.

[MrsOsM]

catmumof1 thank you, ill look into them.

LoniceraJaponica my sister won't be expecting an expensive hen do she's not really like that, we are both pretty easy going so should be ok, thanks x

[butterfly990]

Say to her I've got you covered.

metro.co.uk/2016/03/22/this-genius-invention-helps-brides-go-to-the-toilet-while-wearing-a-wedding-dress-5767103/

[eatthepineapple]

What about somewhere like moonpig? You can make your own and personalise it!